This morning I had this extraordinary experience that I would like to share with my artist buddies in this forum. Please bare with me as I think you will find my story very relevant to this forum. I was in my kitchen with only the light over the stove turned on while starting to cook a breakfast of hash-brown potatoes, fried ham and scrambled eggs. Before scrambling the eggs I first poured some vegetable oil into a pan so that the eggs wouldn't stick. I put the pan on low in order to heat it up while working on the hash browns for which I have a griddle that fits over two of my stove's gas burners. As I came back to the skillet to be used to cook the eggs, I could see this reptilian scale pattern emerging in the heated oil. Sorry, I don't have any photographs. I pilfered the batteries out of my main camera to replace the ones in my dying wireless mouse. Otherwise I would have been temped to repeat the experiment to obtain photographic evidence of this strange phenomenon.

But I have to digress so that I can explain to you the reason I am so interested in this thing. I am a serious dinosaur enthusiast and it is ultimately the reason for me even to be a Terragenic artist myself in the first place. Over the years I have been creating a number of 3D dinosaur models but they don't have fine skin details, only the gross anatomical features. Instead of doing the grueling work of actually putting scalage geometry into my models, it would be greatly preferred to have a "shader" that could do it for me. I envision creating a weight map that could direct the size of the individual scales, but the algorithm would actually create them for me. I haven't heard of any such shader to exist but I could really make use of one. In fact, I think this kind of shader would even be very useful in Terragen itself as I recall seeing even some natural rocks having patterns that are reminiscent of living reptile skin.

In trying to understand the phenomenon I observed while making breakfast, the idea came to me that the oil in the pan is like a miniature weather system. While the oil at the bottom of the pan was heated, it expanded to become less dense and needed to rise to the top of the liquid and be replaced by the colder and denser oil above. Since the hot oil can't go through the oil above it, small "weather cells" are created so that the oil rises in the middle of a cell and the cooler oil sinks in the region around the cell. By mass action, the cells spontaneously form a reptilian skin-like pattern. While the distribution of the heat changes, the "scales" keep changing so that there is a 2D gradient of small to large scales that look exquisite. Really folks, I don't think words can describe how impressive the vision was. It is really a remarkable sight. Perhaps this phenomenon can be used one day to inspired a gifted individual to write the displacement shader that I need to cover my dinosaur models in the places where it is needed. This shader needs to be tied in with the color shaders so that the coloration is coordinated with the scale geometry. For example, where the scales come together might be low in pigmentation while the high places in the centers of the scales are darkest.

I have come very close to buying the low cost version of Z-Brush just for making scale patterns. But that seems so labor-intensive. I'd much rather use a shader. Perhaps it is a job for a GPU. My instinct tells me that a high-end multi-core system could do the computations. If you had a way of doing a preliminary pattern generation and then storing the result then it would greatly speed up process of rendering the models later on. Very cool things to think about. I'd very much like to read what others have to say on this subject.

Yeah I love observing things like this. Working out how things form. It's almost as if there is a simple law behind everything.

Something I heard the other day on a program about gravity that piqued my interest, was that 'matter wants to exist in an area of lower time progression'. The gist is, that time runs slower for things closer to a larger mass like the earth than it does on top of a mountain and will 'gravitate' towards it. But that statement to me put a different perspective on why matter wants to clump together.

The amount of times I sat in traffic on a motorway looking up at the clouds working out how I could replicate the intricacies of their shape with TG fractals. Hah. Way too much time.

Back to your oil scales in the pan, you've kind of worked out, or at least observed a pattern, that has some logic. Heated oil rises through the colder material to give the scale pattern. The Voronoi functions kind have have this shape. Have you thought about using colour from you model texture to influence the scale of a Voronoi shader?

I started reading this with the April Fool's idea in the back of my mind, but found it really believable. Perhaps it also has to do with frequencies of vibration, like you can get sand to shape into patterns with sound/vibrations. Very interesting and before reading Jon's post, thought Voronoi as well. Just to add my 2 cents; I regularly use PF's to make the sizes of a blue node setup like voronoi, and in that sense sizes diversed from an objects color would be useful to get different sizes of snake/dino skin, indeed. Thanks for your story, Pablo.

I started reading this with the April Fool's idea in the back of my mind, but found it really believable. Perhaps it also has to do with frequencies of vibration, like you can get sand to shape into patterns with sound/vibrations. Very interesting and before reading Jon's post, thought Voronoi as well. Just to add my 2 cents; I regularly use PF's to make the sizes of a blue node setup like voronoi, and in that sense sizes diversed from an objects color would be useful to get different sizes of snake/dino skin, indeed. Thanks for your story, Pablo.

Strange coincidence. I wasn't even aware that it was April 1st when I wrote this. I haven't been much of a jokester since one of my pranks backfired in college. I was relieved that it didn't injure my friend. But the prank sort of turned him off to me and I don't think he ever really forgave me. The Voronoi idea is interesting. Though you have to specify a point for every "scale", it is conceivably very much less work than would be shaping each scale.

Yeah I love observing things like this. Working out how things form. It's almost as if there is a simple law behind everything.

There are/is.

It's like the repeated occurrence of Fibonacci sequences in nature, the same set/subset of physical laws underpin many different observed effects in the macro/micro world. It's only at the quantum level that things become unpredictable.

Looks like the April Fools joke was on me after all. A couple of mornings ago I made my usual breadfast but I was a bit more alert this time. I turned the same single light on over the stove and saw the reflection of the light in the (this time) unheated oil. Turns out that the stove light has a "lens" covering that is just a small section of one of those clear plastic sheet covers that are often placed over those long fluorescent tube lights that usually have a texture on them to diffuse the light. This one has a regular bump pattern that is in a honeycomb pattern (that resembles reptilian scales). It dawned on me that the basic scale pattern I had described earlier was not being produced by the hot oil but was merely the image of the light cover being warped by continual motion of the hot oil's surface. So much for my extraordinary "discovery". Certainly the small amounts of oil we are talking about are too small to create the "weather system" phenomenon I thought i was seeing. But I appreciate everyone's indulgence. Every once in a while we have to stand back and laugh at ourselves. Observations are not very reliable when we are in a half-asleep stupor.

Looks like the April Fools joke was on me after all. A couple of mornings ago I made my usual breadfast but I was a bit more alert this time. I turned the same single light on over the stove and saw the reflection of the light in the (this time) unheated oil. Turns out that the stove light has a "lens" covering that is just a small section of one of those clear plastic sheet covers that are often placed over those long fluorescent tube lights that usually have a texture on them to diffuse the light. This one has a regular bump pattern that is in a honeycomb pattern (that resembles reptilian scales). It dawned on me that the basic scale pattern I had described earlier was not being produced by the hot oil but was merely the image of the light cover being warped by continual motion of the hot oil's surface. So much for my extraordinary "discovery". Certainly the small amounts of oil we are talking about are too small to create the "weather system" phenomenon I thought i was seeing. But I appreciate everyone's indulgence. Every once in a while we have to stand back and laugh at ourselves. Observations are not very reliable when we are in a half-asleep stupor.

Hah, that's really funny. There's a phenomena here that relates to this, but has a different scientific explanation (I believe); we have a roof with tiles across my window, and a rather dark brick wall underneath. Every time I look at that wall, just under that tiled roof, I think it's raining (drizzle). Very subtle. But it's not raining at all. I believe it has to do with the information being processed from eye to brain, refreshment of information in the cells, that sort of thing, being disturbed (interference) by that regular pattern above (or even caused by the difference between patterns between upper half and lower half).

Interestingly, I think there *are* patterns in hot oil in a pan, though perhaps not as defined/geometric as you saw. I couldn't find many good images or video of it, but I do think there may be some convective or turbulent action in oil as it heats up in a pan. See here, just *before* he puts water in, for some example:

As it turns out, the phenomenon I was originally seeing was real. I have witnessed it again many times since my retraction so now I have to retract my retraction. It wasn't just a reflection of the light's lens. The oil has to be cold to start with (room temperature is cold enough). Of course the bottom layer heats up because it is next to the bottom of the pan. This bottom layer is trapped underneath the cold top layer but is less dense so a weather system develops to allow the two layers to swap positions. After all of the oil circulates and gets somewhat uniformly hot, the patterns go away. The cold oil is very viscous so that slows the process of mixing down and allows more time for observation. The passing of light through layers of different density causes the visual effect. Pretty cool. Maybe I'll try to get a photo some morning while I'm heating up my skillet to fry my eggs.